Inter-Drive Communication - Toshiba Tosvert RS485 Instruction Manual

6. Inter-drive communication

Inter-drive communication (communication between inverters) are used, for example, when per-
forming speed proportional control or load sharing torque control of two or more inverters without
using a PLC or computer. The command is instructed by the operation from the master inverter's
panel or analog input, etc.
With the Inter-drive communication function, the master inverter continues to transmit the data se-
lected by the parameters to all the slave inverters on the same network. The master inverter uses
the S command for outputting instructions to the slave inverters, and the slave inverters do not re-
turn the data. (See chapter 4.2 "Command".) Network construction for a simple synchronized op-
eration and speed-proportional operation can be created by this function.
* If the master inverter trips, the slave inverters display the blinking error code "t" and come to a full
stop (0Hz).
Restoring the master inverter that has tripped returns the slave inverters to working order.
* With the communication time-out parameters f803 and f804, you can specify what the
slave inverters should do (continue to operate, issue an alarm or trip) if a cable is broken or the
master inverter is turned off during operation.
* To use the inter-drive communication function, select "TOSHIBA Inverter Protocol" (,
=) in the communication protocol selection parameters. "TOSHIBA Inverter Protocol"
(, =) is set for communication protocol selection in Shipment setting. (See "3.
Communication protocol.")
<Conceptual illustration>
Master (60Hz)
VF-AS1
Analog input
<Notes>
Speed command can be transmitted but the run / stop signal is not issued. Slave station should have an indi-
vidual stop signal or the function to stop the action by the frequency reference. (Setting is necessary for :
Operation start frequency, : Operation start frequency hysteresis .)
For continuing the operation by the last received command value in the case of a communication breakdown,
communications time-out time () to trip the slave inverters. The master inverter does not trip even though
the communication breakdown happens. To trip the master inverter, provide an interlock mechanism by installing
an FL fault relay point or the like from the slave side.
Slave 1 (50Hz) Slave 2 (40Hz)
VF-AS1 VF-AS1
33
E6581315
Slave 3 (30Hz)
VF-AS1